1. Technical Field
The present invention relates in general to surgical instruments, and more particularly to biopsy instruments for excising and collecting single or multiple cervical or other soft tissue samples.
2. Background Information
A common out-patient surgical procedure conducted by gynecologists and other physicians is the cervical biopsy. Generally, the procedure involves inserting a speculum through the vagina, and then inserting the distal end of a colposcope into the vaginal opening. A colposcope magnifies the view and shines a light onto the surface of the cervix. The physician methodically views each quadrant of the cervix through the colposcope. Usually, a sterile swab is used to brush a thin coating of dilute acetic acid (vinegar), iodine (Lugol""s solution), or other staining solution over the cervical surface. The physician then immediately views the same area, looking for any whitish, dotted patches along the surface of the cervix, which indicate dysplasia. These findings are charted. A small camera may be attached to the colposcope, if photos are desired. Acetowhite patches usually indicate abnormal cells, which may be cancerous. If abnormal-looking areas are observed during colposcopy, the physician is likely to recommend biopsy of the area. The physician may also observe lesions or other irregularities in the cervical area, which may indicate disease pathology. The size and shape of any lesions, their response to staining, and their color and degree of vascularization are recorded.
Biopsy samples are ordinarily examined under a microscope. The pathologist or technician in the hospital or clinical laboratory first uses a microtome or similar instrument to shave off a thin layer of cells from the tissue sample. The tissue layer is fixed on a slide, and then placed under the microscope. Each sample is carefully examined for any abnormal cells that may indicate a cancerous or precancerous condition. The patient""s physician will be given a pathology report containing the results for each tissue sample. The physician analyzes these results, along with the colposcope observations and Pap smear results, to diagnose whether cervical dysplasia, or another disease, may be present. These results may warrant further steps, such as a cone biopsy, cryotherapy, laser ablation, or possibly radiation therapy or surgical intervention.
Only a very thin layer of tissue (several cell layers thick) is necessary for evaluation by the pathologist. Pulling off large samples from the cervix is unnecessary and may be associated with adverse side effects. This appears to be one of the problems with existing instruments for biopsying cervical tissue: they tear off tissue samples that are often irregular in shape and larger than necessary. Many conventional colpotomy instruments possess small cutting jaws at the distal end which are pushed into the relatively flat cervical surface in order to grasp a section of tissue. The physician then uses the handle to close the jaws. The jaws clench the section of tissue and tear it from the cervix. The colpotomy instrument is withdrawn from the cervix and the sample is transferred from the jaws of the instrument to a sample container. The instrument is inserted once again to obtain an additional sample from a different area of the cervix, and so forth. The biopsy specimen are all placed in plastic containers, which are then transported to a lab and carefully analyzed.
The conventional instruments, which pull and/or bite the cervical tissue, can damage tissue adjacent to the sample sites and cause excessive cervical penetration, pain, and bleeding. These adverse side effects may be associated with a higher likelihood of infection and other complications. The patient may experience more pain and/or cramping during and after the procedure, particularly if she has preexisting gynecological problems. Although bleeding in the area of the biopsy is normally treated with an iron-containing substance (Monsel""s solution) or a solution of silver nitrate, a smaller, more precise biopsy may reduce the necessity for this treatment and would likely decrease vaginal bleeding post-surgically.
The colpotomy instrument of the present invention uses slight suction to pull the cervical tissue into the device end, and then surgically excises a small, precise sample of tissue. In contrast with various types of existing instruments with jaws, the distal end of this instrument need not be pushed into the cervical wall in order to seize a tissue sample. The present instrument allows small, precise, uniformly shaped samples of tissue to be excised, with minimal damage to adjacent tissues. Importantly, the patient experiences less pain, bleeding, and associated discharge during and after the procedure when the instrument of the present invention is used. Morbidity and mortality rates from such procedures, though already low, may be reduced. In summary, the cervical biopsy procedure would be more humane, less painful, more surgically precise, and may be associated with better outcomes when the instrument of the present invention is employed. These numerous advantages may be translated to other soft tissue surgical biopsy procedures.
The present invention is an instrument for biopsying cervical tissue or the like, which comprises:
(1) a distal barrel section, which includes: (a) a hollow barrel having an open, distal end and an opposite proximal end; (b) a piston rod which movably extends substantially through the barrel, the piston rod having a distal end and an opposite proximal end; (c) a cutting mechanism coupled to the distal end of the barrel, the cutting mechanism comprising a movable surgical blade for excising a tissue sample, and having an open, ready position and a closed position; (d) a trigger mechanism coupled to the cutting mechanism for moving the movable blade; and
(2) a proximal handle section coupled to the proximal ends of both the barrel and the piston rod. The piston rod retracts from the distal end of the barrel when the proximal handle section is compressed by a user. When the trigger mechanism is pulled by a user, the cutting mechanism moves from the open position to the closed position.